1. Technical Field
The present disclosure relates generally to an optical lens and an image pick-up apparatus having the optical lens.
2. Description of Related Art
Image pick-up apparatuses are used in a variety of consumer electronic devices, such as notebook computers, personal digital assistants (PDAs), and cellular telephones. An image pick-up apparatus includes a lens module, a base plate, and an image sensor mounted on the base plate. The lens module includes a lens barrel and a number of lenses received in the lens barrel. The image sensor has a top surface facing the lens module and a rectangular optically effective region defined in the top surface. The base plate is fixed to an end of the lens barrel, and defines a through hole for exposing the optically effective region of the image sensor and allowing light to be transmitted from the lens module onto the optically effective region of the image sensor. The top surface of the image sensor includes a round illuminable area. Light transmitted through the lens module is projected onto the illuminable area. The optically effective region of the image sensor is entirely within the illuminable area. The light striking the illuminable area except for the optically effective region is useless, and even though such light is useless, it may have an adverse consequence in that such light may be reflected by an inner wall of the base plate adjacent to the through hole, giving rise to glare during image capture.
Therefore, there is a need for an optical lens and an image pick-up apparatus having the same to overcome the above mentioned limitations.